大腸腫瘍性病変における実体顕微鏡によるpit pattern診断と病理組織診断の比較―特にⅤ型pit patternにおける深達度診断の不一致の原因について

The Reasons Why the Histopathological Diagnosis Sometimes Differ from the Pit Pattern Diagnosis Made by Observation Using the Stereomicroscope

要旨　大腸腫瘍性病変のうち，腺腫および早期癌236病変を用い，実体顕微鏡によるpit pattern診断と病理組織診断の関係，特にⅤ型pit patternにおける深達度診断の不一致の原因を中心に検討した．その原因は腫瘍側のものと人為的もしくは診断者側のものとに大別された．前者には，粘膜固有層への癌の破壊性浸潤，粘膜内と粘膜下層での癌の構造異型の差異，細胞異型が優位のため癌と診断されるなどが含まれ，後者には，生検痕，内視鏡摘除時の熱変性，自己融解，診断時にpit patternを正しく判定できないなどがあった．以上からpit pattern診断，特に人為的影響を受けやすい実体顕微鏡によるそれに際しては，本診断は腫瘍表面のpit patternの乱れや破壊像を見るのみで，必ずしも病理組織診断を反映しているとは限らないとの従来の認識に加え，上記のような原因の存在を考慮しつつ慎重な態度でのぞむべきと考える．

　We examined 236 cases of large intestine venereal disease tumor lesions which differed from the normal pattern of adenoma. The reasons for the discrepancy between the pit pattern diagnosis using the stereomicroscope and the pathological diagnosis were examined. The reasons arose from the tumors themselves and from other artificial factors. The reasons based on the tumors themselves can be found in the early appearance of proliferative change such as desmoplastic reaction, and in the fact that changes deep down in the lesions have not yet appeared on the surface.

　The reasons based on artificial factors were such things as biopsy scar, changes brought about by heat generated by EMR, self-fusion, etc.

　Pit patterns discerned by stereomicroscopy are easily affected by artificial influences arising from the investigation process, and this also could account for the difference in diagnosis made by stereomicroscopic observation of pit pattern and that made by histopathology.

　While carrying out stereomicroscopic observation, the artificial influences involved should be kept in mind.